This invention generally relates to transverse flux electric motors. More particularly, this invention relates to a strategy for fabricating the components of a transverse flux motor in a practical and cost-effective manner.
It has recently become apparent that there are significant advantages to utilizing gearless propulsion systems in elevator and escalator systems, for example. With a gearless propulsion arrangement, there are no gear trains between the propulsion machine or mechanism and the driven components (such as the sheaves in an elevator system). Gearless propulsion systems typically have fewer components and are more compact than traditional geared arrangements. An additional advantage is that gearless propulsion systems reduce acoustic noise and simplify maintenance procedures.
One challenge presented in attempting to use gearless propulsion systems is that they typically require electric motors, which often prove difficult to make with the desired performance characteristics. Permanent magnet motors are advantageous because they are capable of developing higher torque densities with higher efficiency compared to induction or switched reluctance arrangements. Permanent magnet transverse flux motors are capable of producing even higher torque densities than permanent magnet brushless motors.
A significant challenge is presented when attempting to build such a system because transverse flux machines are typically relatively expensive. The armature of a transverse flux motor has a complicated structure. Typical attempts include laminating arc-shaped sheets and embedding conductive coils in the laminated stack by arranging the coils within concentric slots. Although the process would be improved by utilizing wedge-shaped lamination sheets formed by a hot rolling process, that approach is undesirably expensive.
There is a need for an improved method of making the components of transverse flux electric motors that avoids the complications and expenses associated with current approaches. This invention addresses those needs while avoiding the shortcomings and drawbacks of the prior art.